Long Covid Studies

Overview of studies on the long-term effects of Covid-19.

Corona long-term effects - studies at a glance

As of June 2021, there are a total of 3,723,234 people in Germany who have been or are currently infected with coronavirus. It is difficult to determine the frequency of Long Covid. A press release from the German Society for Respiratory Medicine (DGP) reports that about 10 % of these people are estimated to have to deal with the long-term effects of coronavirus.

Studies into the long-term effects of coronavirus have yielded a wide range of results. The following is a summary of individual studies into Long Covid:

Study from the UK: 20% report symptoms 4 weeks after Covid-19 infection

Data on the long-term effects of coronavirus from the UK report protracted symptoms in 20 % of patients even 4 weeks after infection. Symptoms are still reported in 10 % of patients 6 months after infection. In particular, chronic fatigue may still be present 4 weeks after infection in as many as 35-34 % of cases and in as many as 16-55 % of cases 12 weeks after infection [1].

Meta-analysis shows 80% of infected individuals with long-term symptoms

  • A large-scale meta-analysis of Long Covid based on 47910 participants revealed that 80 % of the study participants experienced one or more long-term symptoms following SARS-CoV-2 infection. The three most common Long COVID symptoms were fatigue (58 %), headache (44 %) and attention deficit (27 %). Furthermore, hair loss (25 %), dyspnoea (24 %) as well as ageusia (23 %) and anosmia (21 %) were observed [2].

Lancet study shows 76% of Covid-19 patients still with symptoms after 6 months

One study into Long Covid published in the Lancet involving 1,733 patients first diagnosed with COVID-19 in Wuhan, China between January and May found that 76 % of Covid-19 patients had at least one symptom six months after the onset of symptoms. The cohort study, which investigated the long-term effects of Covid-19 infection in patients in Wuhan, China, shows that the most common persistent symptom is fatigue or muscle weakness (63 % of patients), with patients also frequently suffering from sleep disorders (26 %). Anxiety or depression was reported by 23 % of patients [3].

Irish Long Covid study finds that 60 % of the study participants reported that they had "not fully recovered" after 75 days

A Long Covid working group from Ireland also found that persistent fatigue, dyspnoea and discomfort are common after acute Covid-19 infection. After an average of 75 days between diagnosis and follow-up, over 60 % of the study participants reported that they had "not fully recovered". However, none of the outcomes measured in this study were related to the initial severity of the disease [4].

Study from Bangladesh: Post- Covid-19 syndrome in 46% of the patients

A study from Bangladesh found that the incidence of Post- Covid-19 syndrome was 46 %. In all, 105 (30 %) patients showed at least one symptom following Covid-19, while 57 (16 %) patients showed multiple symptoms. Post-viral fatigue was the most common feature (117). Other symptoms included persistent cough (8.5%), dyspnoea after exertion (7 %), headache (3.4 %), dizziness (2.3 %) and sleep-related disorders (5.9 %) [5].


  • [1] Greenhalgh, T., Knight, M., Court, C., Buxton, M., & Husain, L. (2020). Management of post-acute Covid-19 in primary care. BMJ, 370:m3026. DOI: 10.1136/bmj.m3026
  • [2] Lopez-Leon, S., Wegman-Ostrosky, T., Perelman, C., Sepulveda, R., Rebolledo, P.A., Cuapio, A., & Villapol, S. (2021). More than 50 long-term effects of Covid-19: a systematic review and meta-analysis. medRxiv, 2021.01.27.21250617. DOI: https://doi.org/10.1101/2021.01.27.21250617
  • [3] Huang, C., Huang, L., Wang, Y., Li, X., Ren, L., Gu, X.,& Cao, B. (2021). 6-month consequences of Covid-19 patients discharged from hospital: a cohort study. Lancet, 397, 220-232. DOI: doi.org/10.1016/ S0140-6736(20)32656-8
  • [4] Townsend, L., Dowds, J., O’Brien, K., Sheill, G., Dyer, A., O’Kelly, B., … & Bannan, C. (2021). Persistent poor health post-Covid-19 is not associated with respiratory complications or initial severity. AnnalsATS. DOI: https://doi.org/10.1513/AnnalsATS.202009-1175OC
  • [5] Mahmud, R., Rahman, M., Rassel, M., Monayem, F., Sayeed, S., Islam, M. S., & Islam, M. M. (2021). Post-Covid-19 syndrom among symptomatic Covid-19 patients. A prospective cohort study in a tertiary care center of Bangladesh. PLOS ONE, 16(4). DOI: https:// doi.org/10.1371/journal.pone.0249644